Added mutex locks in register_target.cpp and created a multithreading test. Fails.

src/register_target.cpp

@@ -21,6 +21,7 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
+#include <mutex>
 #include <string>
 #include <unordered_map>
 #include <migraphx/register_target.hpp>
@@ -33,6 +34,9 @@ inline namespace MIGRAPHX_INLINE_NS {
 void store_target_lib(const dynamic_loader& lib)
 {
     static std::vector<dynamic_loader> target_loader;
+    std::mutex mutex;
+    std::unique_lock<std::mutex> lock(mutex);
+
     target_loader.emplace_back(lib);
 }
 
@@ -46,14 +50,28 @@ void register_target_init() { (void)target_map(); }
 
 void unregister_target(const std::string& name)
 {
+    std::mutex mutex;
+    std::unique_lock<std::mutex> lock(mutex);
     assert(target_map().count(name));
     target_map().erase(name);
 }
 
-void register_target(const target& t) { target_map()[t.name()] = t; }
+void register_target(const target& t)
+{
+    std::mutex mutex;
+    std::unique_lock<std::mutex> lock(mutex);
+
+    target_map()[t.name()] = t;
+}
 
 target make_target(const std::string& name)
 {
+    // debug
+    for(auto pp : target_map())
+        std::cout << pp.first << "\n";
+
+    std::mutex mutex;
+    std::unique_lock<std::mutex> lock(mutex);
     if(not contains(target_map(), name))
     {
         std::string target_name = "libmigraphx_" + name + ".so";

test/targets.cpp

@@ -23,6 +23,9 @@
  */
 #include <migraphx/register_target.hpp>
 #include <migraphx/target.hpp>
+#include <migraphx/par_for.hpp>
+#include <mutex>
+#include <thread>
 #include "test.hpp"
 
 TEST_CASE(make_target)
@@ -50,4 +53,21 @@ TEST_CASE(targets)
     EXPECT(ts.size() >= 1);
 }
 
+TEST_CASE(concurrent_targets)
+{
+    std::vector<std::thread> threads;
+
+    for(auto i = 0u; i < 10000; i++)
+    {
+        auto thread_body = []() {
+            auto ref_target = migraphx::make_target("gpu");
+            migraphx::register_target(ref_target);
+        };
+
+        threads.emplace_back(thread_body);
+    }
+    for(auto& tt : threads)
+        tt.join();
+}
+
 int main(int argc, const char* argv[]) { test::run(argc, argv); }